It has long been known that products of the aloe plant, particularly, aloe vera L. (aloe barbadensis Miller) are useful as medicaments in the treatment and healing of a wide variety medical disorders. From ancient times, to the present, aloe gel has been reported to be useful in the treatment of medical disorders in almost every field of medicine from psychiatry to oncology, e.g., insomnia, insect bites and stings, infections, herpes, rheumatism, etc., and aloe is known to be particularly effective in treating skin-related disorders.
Many attempts to identify and isolate therapeutically active components from aloe plants have been made in the prior art. For example, U.S. Pat. No. 3,103,466 is directed to medicaments useful for treating surface wounds that include a polyuronide isolated from aloe gel which comprises a polysaccharide having chemically bonded thereto one or more hexuronic acid radicals having a molecular weight from about 374,000 to 275,000 or the non-toxic salts thereof.
U.S. Pat. No. 3,362,951 is directed to a therapeutically active polysaccharide derived from the juice of aloe plants by mixing the juice with a dilute aqueous solution of phosphomolybdic acid; separating the resulting precipitate from the aqueous solution; mixing a lower aliphatic polar solvent with the aqueous solution; separating the resulting blue-green precipitate therefrom and adding aqueous hypochlorous acid until the precipitate turns essentially white and recovering the white precipitate which when washed with a water soluble polar solvent is a highly pure polysaccharide in the form of long polymer chains (molecular weight about 420,000 to 520,000) comprised of repeating units containing substantially equal amounts of glucose and mannose residues, a small proportion of glucuronic acid residue and chemically bound calcium.
U.S. Pat. No. 4,225,486 is directed to a medicinally useful glycoprotein isolated from aloe plants and having a molecular weight of about 18,000, a protein to sugar ratio of 8 to 2 by weight and other specified properties. The glycoprotein is prepared by precipitating a fraction from aloe juice with ammonium sulfate; dialyzing the precipitate to remove the ammonium sulfate; acidifying the dialyzed solution and collecting the precipitate; dissolving the precipitate in buffer and separating the protein product on a Sephadex G-200 column.